Development of Three Dimensional Kinetic Monte Carlo (3D-KMC) Grain Growth Simulator Based on Tight Binding Quantum Chemical Molecular Dynamics and Its Application to the Analysis of Thermal Grain Growth of CeO₂ and Rh/CeO₂

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The electronic configuration between the interface of supported Rh and CeO₂ (111) surface was investigated by Tight Binding based Ultra Accelerated Quantum Chemical Molecular Dynamics method (TB-UAQCMD) at 1073 K. Time courses of bond energies of Rh-O (-Ce) plots for 5000 fs showed gradual increases of bond strength between oxygen and rhodium atoms in the uppersurface of the CeO₂ (111). This caused the anchoring effect of Rh-O (-Ce) bonds in the form of Rh-O (-Ce). Therefore total energies of the Ce-O bonds in the Rh/CeO₂ were found to become more stable than that in the pure CeO₂. The activation energy of grain growth of Rh/CeO₂ nanoparticles was estimated by this deviation in these Ce-O bond energies. Experimentally observed suppression in the grain growth of Rh/CeO₂ nanoparticles relative to those without Rh was quantitatively reproduced by three dimensional Kinetic Monte Carlo method (3D-KMC).